The present invention relates to a machine for backing-off and/or grinding drifting spindles provided with teeth, essentially spindles of any type, namely of round, flat or helical shape, the machine comprising a sliding table and a grinding spindle mounted on a support which can be oriented and moved transversely with respect to the table.
During the backing-off or grinding of a spindle on machines of this type, the spindle is fixed on the sliding table, whereas the grinding wheel, inclined in the desired position, is advanced either transversely or vertically with respect to the spindle in order to carry out the backing-off or grinding operation and moves away in the same manner. However, for certain types of spindles, the operation is more complicated. In fact, at the time of plunging grinding, for example, of a round spindle by a conical grinding wheel, the grinding wheel cannot be advanced transversely in order to grind the circular teeth of the spindle, since there is a danger of grinding part of the circular periphery of the respective teeth. Normally, for grinding a round spindle the grinding wheel is lowered vertically, by lowering the column which supports it, into the space between teeth and the spindle is advanced until the face to be ground comes into contact with the grinding wheel. The operations are reversed after grinding.
These operations involve a considerable waste of time on the one hand and on the other hand the space between two consecutive teeth must be sufficiently large in order that the grinding wheel can be lowered to the grinding height and wait for the arrival of the tooth to be ground without touching the backing-off of the preceding tooth. The mass to be moved is also considerable and contrary to the laws of ergonomics.